If anybody's looking for a good, fresh SF with just the right infusion of humour and thought-provoking capital-i Ideas, here it is.

Concept-wise, it's perhaps not entirely original (what is?) but is handled well enough that I can't think of anything similar I've read.

Characterisation is great--as expected of two masters--with bonus points for plenty of strong female characters.

There are clear Pratchett moments (the device to travel to alternate worlds is powered by a potato, and there's a sentient AI with his usual quirky style of humour), but with none of the dredging up of stale jokes that has been marring his latest Discworld novels in my unqualified-and-slightly-foxish opinion.

The prose is much cleaner than anything Pratchett's written lately, almost effortless to read but still beautiful at points. I haven't read anything else by Baxter, but if the rest of his stuff is like this I'm a fan.

I'll admit to be being torn on thie book.I'm a Pratchett fan and so I'm very interested in this collaboration.Butbaxter really burned my butt iwth his book Titan. Oh the science and engineering looked dead on to me, but the man didn;t research the american political system at all and it showed. several times I wanted to throw the thing against the wall, and I had already read and really enjoyed a number of Baxter Books.

There are definitely a few sentences where the authors exhibit that stereotypically British assurance that the rest of the English-speaking world is a strange and nonsensical apparatus.

For the most part, though, they don't stand out.

My favourite quip is one where a police officer comments that the American people had very suddenly had gun control imposed on them and did not know how to deal with it. (Iron, for reasons not known in the book, does not travel to alternate realities like most metals.)